The present invention relates to a remote-controlled method of drilling, analyzing, and stabilizing a subsurface formation. More particularly, the present invention relates to drilling, analyzing, and stabilizing a remotely located subsurface formation.
The methods used in exploring formations are of two general types: direct and indirect. Direct methods entail drilling, excavating and sampling. Indirect methods involve chemical analysis and surveys of properties such as radioactivity, reflectivity, gravity, magnetism, seismic waves and heat flow. The indirect approach often begins with radar mapping and photographic surveying from orbiting satellites equipped with optical-mechanical infrared scanners and/or multispectral scanners to reveal characteristics such as groundwater movement, hydrothermal areas, specific types of subcropping rocks associated with mineral concentrations, etc. Physical measurements are widely used in the search for oil and minerals and in building-foundation investigation. Chemical prospecting techniques are commonly employed to measure trace contents of certain elements in rock, water, vegetation, and other surface materials that may indicate the presence of a buried body of ore in a given area.
Traditionally, scientific investigators have relied heavily on physical measurements, particularly of seismic waves, to secure information about Earth""s interior and its dynamic processes. For example, during the early 1980s seismic investigations of the Appalachian Mountain region of the United States resulted in important discoveries about continent formation. Additionally, exploration of the seafloor and its gravitational and magnetic properties has contributed to the development and widespread acceptance of plate tectonics, a concept that has not only revolutionized scientific understanding of the Earth""s dynamic features but has led to the discovery of rich deposits of valuable metals on the ocean bottom as well.
Because indirect methods are applied to the surface of a formation, data must be extrapolated to reveal information about the formation interior. Direct methods, however, are applied to the surface and subsurface of a formation. As a result, information obtained from direct sampling is more precise and thus direct sampling is preferred.
Direct sampling, generally by means of boreholes, is often required in order to make positive identification of substances and to determine the extent of their presence, as well as to choose appropriate methods of recovery. Unfortunately, drilling and other techniques of direct exploration have typically been less significant in the scientific study of remotely located formations, because of the high cost and limited technology available. Therefore, there exists a need to provide a cost-effective method and apparatus that allows direct autonomous sampling of remotely located formations.
In order to support theories based on information obtained from indirect methods, direct sampling data is needed. The present invention provides an unmanned, remote-controlled method, system and apparatus for drilling, analyzing, and stabilizing subsurface formations.
In accordance with a preferred embodiment of the present invention, a remotely operable drilling apparatus for investigating a formation includes a landing craft disposed upon the formation, a bottomhole assembly in communication with the landing craft through a communications link wireline. The preferred bottomhole assembly includes a borehole gripping mechanism, an extension/retraction mechanism, a torque drive assembly, a coupling mechanism, and a tool.
In accordance with an alternate preferred embodiment of the present invention, a remote drilling method includes deploying a landing craft to the surface of the formation, deploying a bottomhole assembly from the landing craft to the formation, and drilling, logging, and sampling using equipment provided on the landing craft.